[UNCLASSIFIED]RE: [clug] Dual core or dual processor?

[Antti.Roppola at brs.gov.au]

Hi Hugh,

I'm interested too in that I'm eyeing off one of the AMD dual core
Opterons as host for virtual dev systems (Xen, maybe VM Ware), then
there's core duo which is also two CPUs on the one die.

I was recently reading that HyperThreading ala Pentium 4 was not as
much of a performance boost as people hoped. I don't have the reference,
but since the Core Duo CPU's do not inclde HT, one can guess:
 http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2795

HT puts two stacks on the one shared core. OTOH, the dual core and traditional
SMP systems should be parallel all (most?) of the way through. My guess would be
That there is not much difference between on-die SMP and separate CPUs. Some of the
dual core desktops are quite cheap compared to tradtional SMP (hence my interet).

Antti

-----Original Message-----
From: linux-bounces+antti.roppola=brs.gov.au at lists.samba.org [mailto:linux-bounces+antti.roppola=brs.gov.au at lists.samba.org] On Behalf Of Hugh Fisher
Sent: Monday, 27 November 2006 11:24 AM
To: Canberra Linux User Group
Subject: [clug] Dual core or dual processor?


I'm looking into options for a new PC that will be mostly running a realtime 3D graphics/virtual reality development system.

The plan is to have two main threads. One will be the 3D scene graph renderer, which even with modern 3D graphics cards means a lot of floating point crunching for high level culling, head tracking, morphing, and whatever. The other is a Python thread which creates and controls the 3D scene, running high level logic and 'game AI' type code such as flocking.

Each thread has a few megabytes of code and can have tens of megabytes of data. They are threads rather than processes because the scene graph and the Python objects have lots of references into each other, so share address space. Every time a frame is rendered the scene graph code gets rendering parameters from Python code, and Python code changes the scene graph.

My question is, will a dual processor system perform significantly better than one dual core CPU on this kind of workload? My first guess would be yes, but I really have no idea how a 'hyperthreaded' system actually schedules threads and/or manages cache and memory.

Any advice, or pointers to advice, appreciated.

	cheers,
	Hugh
--
linux mailing list
linux at lists.samba.org
https://lists.samba.org/mailman/listinfo/linux

---------------------------------------------------------------------- 
IMPORTANT - This message has been issued by The Department of Agriculture, Fisheries and Forestry (DAFF).  The information transmitted is for the use of the intended recipient only and may contain confidential and/or legally privileged material.  It is your responsibility to check any attachments for viruses and defects before opening or sending them on.  
Any reproduction, publication, communication, re-transmission, disclosure, dissemination or other use of the information contained in this e-mail by persons or entities other than the intended recipient is prohibited.  The taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited.  If you have received this e-mail in error please notify the sender and delete all copies of this transmission together with any attachments.  If you have received this e-mail as part of a valid mailing list and no longer want to receive a message such as this one advise the sender by return e-mail accordingly.  Only e-mail correspondence which includes this footer, has been authorised by DAFF 
----------------------------------------------------------------------